A device that builds a product model by adding processing information to three-dimensional geometrical data (product modeling device) has been developed to facilitate the processing of a three-dimensional shape on a processing machine. In the product modeling device, processing site models that include shapes of processing areas and processing attribute information (such as process operations) corresponding processing patterns are prepared in advance in a processing site library. Then, on a computer-aided design (CAD) device, a blank model and a processing site model of the processing site library are combined to build a product model to which processing information is added (see Patent Document 1, for example).
Furthermore, a device that automatically generates an NC program based on the three-dimensional geometrical data in a CAD device has been suggested. This device extracts a shape of a processing area that corresponds to a difference between the three-dimensional product data and the blank geometrical data, and divides the extracted shape of the processing area into sets of shapes of areas that are to be subjected to basic processing. Then, a process operation, conditions and the like are determined for the shape of each basic processing area to generate an NC program (see Patent Document 2, for example).
In addition, a device has been suggested, which generates an NC program by extracting a specific geometrically characteristic site from the three-dimensional geometrical data of a product and generating processing procedure information such as a process operation and conditions and processing area information for the extracted geometrically characteristic site (see Patent Document 3, for example).    Patent Document 1: Japanese Patent Application Laid-open No. 2003-177811    Patent Document 2: Japanese Patent Application Laid-open No. 2006-53945    Patent Document 3: Japanese Patent Application Laid-open No. 2002-189510